The role of mycoplasma, chylamidia and other non-viral agents in diseases of man particularly those associated with perinatal disease, infertility or neurological diseases has been studied. Reproductive tract samples from men studied for presence of these organisms, classical strain mycoplasma, T-strain mycoplasma and chylamidia were recovered from both men without clinical disease and from those with genital tract infections. Routine monitoring of culture from experimental viral studies and efforts to develop new techniques to monitor tissue culture for non-viral agents have been continued.